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Travel through wormholes is possible, but slow

231 points| lelf | 7 years ago |phys.org | reply

179 comments

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[+] noobermin|7 years ago|reply
I'm not sure if this is the researchers' issue or is an issue with the scientific press, but it would help if the "discoveries" theorists made with their hitherto unestablished and untested theories like various string and QG based theories were not touted as discoveries about the real world.
[+] krastanov|7 years ago|reply
"Discoveries" about the mathematical structure of these theories are actually incredibly important even if no current day experiment can conceivably test them. Special and general relativity were discoveries made in this way (at least to an extent), and now general relativity is important for the proper functioning of technology as "trivial and boring" as GPS. Even earlier in our history, much of thermodynamics was developed in a similar fashion.

See the sibling comment for another version of this argument, but finding the weird mathematical coincidences between the competing mathematical theories of nature is very useful. In other words, there are mathematical and logical tests that can be as important as experimental tests for the progress of our understanding of nature.

[+] PaulHoule|7 years ago|reply
QG is funny.

There are some results around QG, such as holography, which seem to be universal. That is, they make sense with strings, loop quantum gravity or any of about ten other lines of work that people can do quantum gravity calculations with today.

If you can prove that all of those have to say the same thing, that is a powerful result and probably means something about our world.

It seems pretty reasonable that wormholes could exist so long as they don't form closed-timelike curves, so I think these people are getting at the quantum roots of the "cosmic censorship principle".

[+] andbberger|7 years ago|reply
I think it goes beyond the scientific press. There seems to be a general tendency to squash the intricacies of anything and react impulsively to some red herring or whatever; such comments dominate all online forums I've ever seen.

Here is a fantastically interesting article that maybe has some new insight on the nature of spacetime; top comment on HN thread about it is some person loudly and incredibly pretentiously mistaking their own misunderstanding of the intricacies of 'truth' in science (and how there are different levels) for some flaw in the work itself.

You know, the underlying sentiment here is a good one. How do we know what we know, what do our theories really tell us, etc. All excellent questions. But you didn't express that at all, instead you say these things shouldn't be 'touted as discoveries about the real world.'

That's all you man! No theorist ever has wanted people to think this of their work, it slaughters the beautiful intricacies of it and leads to public relations disasters like this.

Don't go misunderstanding shit and then confidently be blaming it on other people man. Rhetoric matters.

The whole "it's just a theory" thing has done so much harm to public understanding and appreciation. It's an impossible starting point for a conversation, if you think "it's just a theory", you're not wrong, as much as entirely missing the point. How do you start with that and get to an understanding that things aren't always absolutely right or wrong, that contexts and assumptions matter, that things can be true in one setting (the math) and uncertain in another (the real world). That for most things what we are more than anything is uncertain. That there are many different kinds of uncertainty.

How are the subtle intricacies of things (that the answer to almost everything starts with "well, that depends...") supposed to survive forums where conversations are heavily selected for ability to grab attention? Not a rhetorical question, if you got ideas I want to hear them.

PS noobermin, I don't mean to be overly-critical of you although it sure sounds like it. I'm using 'you the pronoun'. Just something I think about a lot that you catalyzed me into trying to express...

[+] Johnny555|7 years ago|reply
I think for anyone for whom this theory is at all relevant, it's already clear that this is a theory, not a proven fact.

The fact that its theoretical is mentioned in the article for anyone that bothered to read past the first few paragraphs. For the rest of us, it just makes for interesting party conversation whether the theory pans out or not (which couldn't be proven by actually transiting a wormhole within any of our lifetimes)

So no harm, no foul -- anything that makes theoretical science interesting in the popular press is a win in my book.

[+] SketchySeaBeast|7 years ago|reply
Can someone point out where the article says why it's slower? I'm having difficulty unpacking:

"The new theory was inspired when Jafferis began thinking about two black holes that were entangled on a quantum level, as formulated in the ER=EPR correspondence by Juan Maldacena from the Institute for Advanced Study and Lenny Susskind from Stanford. Although this means the direct connection between the black holes is shorter than the wormhole connection—and therefore the wormhole travel is not a shortcut—the theory gives new insights into quantum mechanics."

Why is the wormhole not a shortcut?

[+] philipov|7 years ago|reply
Based on the colloquia I watched by Lenny Susskind, the problem is that you can put something into a wormhole, but to get it out the other end, you have to carry the encoding you get to the other end of the wormhole to decode the output. Because the distance to the singularity grows at the speed of light, the length of the wormhole is essentially infinite. It is only the operator you get from putting the object into the wormhole that lets it tunnel through that infinity, so no shortcut.

EDIT: Here is the lecture I'm referring to: https://www.youtube.com/watch?v=nEDFh8ma9zM

[+] eigenschwarz|7 years ago|reply
The Average Null Energy Condition (ANEC) makes it so there can not be a traversable wormhole joining two otherwise disconnected regions of spacetime. So by construction, any infinite null geodesic (a light ray) which makes it through the wormhole must be chronal (causally connected). This means there can be no traveling faster than light over long distances by going through one.
[+] Abishek_Muthian|7 years ago|reply
>To date, a major stumbling block in formulating traversable wormholes has been the need for negative energy, which seemed to be inconsistent with quantum gravity. However, Jafferis has overcome this using quantum field theory tools, calculating quantum effects similar to the Casimir effect.

Prof. Stephen Hawking has explained the Casimir effect in hist last book 'Brief Answers to the Big Questions' in the chapter talking about Time Travel with Wormholes.

"Imaging that you have two parallel metal plates a short distance apart. The plates act like mirrors for the virtual particles and anti-particles. This means that the region between the plates is a bit like an organ pipe and will only admit light waves of certain resonant frequencies. The result is that there are a slightly different number of vacuum fluctuations or virtual particles between the plates than there are outside them, where vacuum fluctuations can have any wavelength. The difference in number of virtual particles between the plates compared with outside the plates means that they don't exert much pressure on one side of the plates when compared with the other. There is thus a slight force pushing the pates together. This force has been measured experimentally. So, virtual particles actually exist and produce real effects.

Because there are fewer virtual particles or vacuum fluctuations between plates, they have a lower energy density than in the region outside. But the energy density of empty space far away from the plates must be zero. Otherwise it would warp space-time and the universe wouldn't be nearly flat. So the energy density in the region between the plates must be negative"

[+] jaequery|7 years ago|reply
When ever I think of traveling through a wormhole/blackhole, I imagine you would be squished and crushed and come out the other end as pure vaporized energy.

This makes me wonder, if there is the potential for our beings (or things) be able to be vaporized and then recreated to original form.

If we are just mass and particles, this should be possible?

[+] jniedrauer|7 years ago|reply
If you could 3d print things at the atomic level, then you could instantly advance the human race to a post scarcity society. It's the holy grail of 3d printing and of course everyone wants to do it.

Your question has philosophical implications beyond just the mechanics, however.

[+] lupire|7 years ago|reply
Uncertainty principle says...probably not. It's impossible to make a complete copy of the pattern.

Even aside from that -- it's unlikely to be practical to scan something down to the smallest level level of matter, because the tools we use to manipulate things can't manipulate things smaller than their own finest details. So there's a "glass wall" in that you can only replicate things less finely detailed than the replicator. That works fine for macroscopic things (that's why you can buy a 3D printer today), but is implausible for things that we believe to be as finely detailed as our machines.

[+] JoeAltmaier|7 years ago|reply
Its all about information. The order of atoms to make a person is information. No information passes thru the event horizon of a black hole.

So, no.

[+] GenericsMotors|7 years ago|reply
You've just described a Stargate from the SG1 universe :)

Gates disintegrate objects that pass their event horizon, transmit the energy and "pattern" of the object to the exit gate which rebuilds them.

Essentially everyone in that universe that has stepped through a Stargate has "died" and it's their copies currently walking around.

[+] vectorEQ|7 years ago|reply
"To date, a major stumbling block in formulating traversable wormholes has been the need for negative energy, which seemed to be inconsistent with quantum gravity. "

it appears thus, most humans are inconsistent with quantum gravity :D:D

[+] krastanov|7 years ago|reply
I would urge people interested in this topic to read the hard scifi work of Greg Egan. In particularly, Diaspora. It is fascinating how much overlap is between this mathematical work and his work of "mathematical fiction".
[+] philwelch|7 years ago|reply
It seems to me that the speed of light, like conservation of energy, is just one of those fundamental “no free lunch” rules of physics that we just plain can’t cheat.
[+] drdeca|7 years ago|reply
Why doesn’t this violate the topological censorship result?
[+] dosy|7 years ago|reply

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[+] aurailious|7 years ago|reply
I'm 100% certain Stargate isn't a documentary.
[+] jbob2000|7 years ago|reply
We would know. Either the secret space program requires enough exotic materials and science that you wouldn't be able to hide it OR it doesn't require that, so it's simple enough that any one of us could stumble upon it.

Trillions of dollars vanished because humans are probably more greedy than they are curious.

[+] diminoten|7 years ago|reply
A conspiracy that large would leak. This fact kills most conspiracy theories -- humans can't help but share cool shit.